import numpy as np
import cv2

#Create a black image
img = np.zeros((512,512,3),np.uint8)

pts=np.array([[10,5],[20,30],[70,20],[50,10]],np.int32)
pts = pts.reshape((-1,1,2))
cv2.polylines(img,[pts],True,(0,255,255)) 

cv2.namedWindow('image',cv2.WINDOW_NORMAL)
cv2.resizeWindow('image',1000,1000)#frame size
cv2.imshow('image',img)
cv2.waitKey(0)
cv2.destroyAllWindows()
